Engel Marginal Subgroups in Pro-Lie Groups

The position of the n-Engel marginal and verbal subgroups is placed between appropriate terms of the (upper or lower) central series of an abstract group, when n is small enough. In case of compact (Hausdorff) groups, the presence of a topological structure allows us to consider larger values of n, again controlling very well the position of these subgroups with respect to the terms of the central series. We observe a similar behaviour in the wider context of pro-Lie groups.